Ketamine was developed in 1962 by Parke-Davis, a subsidiary of the pharmaceutical company Pfizer, as an anesthetic alternative to Phencyclidine (PCP). Commercial brands of Ketamine include Ketalar, Ketaset, Ketmex; Ketotal, Ketamine-500 (Astrapin) and Imalgen. The name Ketamine is derived from "keto-mine" named after the ketone C=O group bonded to carbons, as well as an amine group. Ketamine was first administered to American soldiers during the Vietnam War, and is widely used today as a battlefield anesthetic in developing nations, as well as in veterinary medicine. The substance was first used in psychiatric and other academic research in the 1970s. Recreational use dates back to around 1967 and became increasingly popular through the end of the 20th century, particularly at raves, concerts, music festivals and other parties. Recreational names fro Ketamine include, "K", "Ket", "Special K"; "Kitties", "K2", "Vitamin K"; "mean green" and "rockmesc". Ketamine can currently only be used legally by health professionals, for university research purposes, or with a doctor's prescription.
Ketamine, a hydrochloride salt, is pharmaceutically classified as an NMDA receptor antagonist. It is listed as a Schedule III drug under The United States Controlled Substances Act; in the United Kingdom, Ketamine is outlawed and listed as a Class C drug; in Canada, Ketamine is classified as a Schedule I narcotic;
Ketamine comes as a liquid or a powder; as a powder, it can be insufflated (inhaled), injected, or taken orally. Heavy Ketamine users exclusively use intramuscular injection as their primary method of administration because it bypasses the liver, works more efficiently and induces a smoother high. Oral use requires more of the drug.
For medical purposes, Ketamine is used as an anesthetic to treat patients undergoing minor medical procedures and asthmatics or patients with chronic obstructive airway disease. Ketamine is commonly used as part of a cream, gel, or liquid for a topical application for nerve pain; it is also used in emergency medicine to treat patients suffering from severe trauma, in emergency surgery in war zones, and to supplement spinal and epidural anesthesia at low doses.
In veterinary anesthesia, Ketamine is often used for its painkilling effects on dogs, rabbits, cats, rats, and other small animals. It is the primary anesthetic used in equine surgery.
Low-dose Ketamine is also recognized for its effectiveness in treating patients with complex regional pain syndrome (CRPS). In some neurological ICU settings, Ketamine has been used in cases of prolonged status epilepticus; there is some evidence that NMDA-blocking effect of Ketamine protects neurons from glutamatergic damage during prolonged seizures.
In treating patients who suffer from CRPS, researchers found that some patients made a significant recovery from associative depression. Ketamine has also been used as an experimental drug to treat alcoholism
and heroin addiction
, and the dissociative anesthetic effects of the drug have also been used in postoperative pain management.
Ketamine has a wide range of effects when consumed by humans. Short term effects include increased heart rate, slurred speech, confusion and disorientation; out-of-body experience, shifts in perception of reality, meaningful spiritual experiences; dissociation of mind and body, open and closed-eye visuals, enhanced sense of connection with the world; nausea, sedation, hypersalivation; hypertension, tachycardia, respiratory depression; euphoria, sense of calm and serenity, pleasant mental and/or body high; analgesia, ataxia, distortion or loss of sensory perceptions, and significant change in perception of time. In patients suffering from depression, Ketamine has been known to decrease depressed mood, suicidal tendencies, somatic anxiety and hypochondriasis.
When injected into the leg, Ketamine onset for intramuscular administration is about one minute; when administered orally, Ketamine is rapidly metabolized into norketamine, which induces sedating effects.
Ketamine induces similar effects as Phencyclidine (PCP) and dextromethorphan (DXM), but is not as long acting as either drug. Ketamine users experience dissociative states (depersonalization and derealization); users may experience a "K-Hole", a dissociative state with effects that mimic schizophrenia; users may also experience worlds or dimensions that are ineffable, unaware of theor individual identities. Users have also reported sensations of falling, fast and gradual movement and flying, and experiencing psychotic reactions and shared hallucinations and thoughts with other users.
Chronic use of Ketamine may lead to cognitive impairments and memory loss, and may increase the effects of other sedatives including benzodiazepines, barbiturates, opiates, anesthetics, and alcoholic beverages.
Drugs that produce similar effects to Ketamine include Phencyclidine (PCP), Dextromethorphan (DXM), Ecstasy (MDMA); gamma-Hydroxybutyric acid (GHB) and Rohypnol.
Ketamine is not physically addictive, but it is psychologically addicting due to desirable effects and short duration. Evidence indicates that users can easily build a tolerance to Ketamine after continued use, lasting for about three days, followed by emotional or psychological dependence. Chronic users can develop a permanent tolerance so that, months after use, they are unable to experience Ketamine's psychedelic effects ever again.
Cessation of Ketamine use can trigger emotional withdrawal symptoms, including depression, irritability, insomnia; tension, twitchiness, short attention-span; restlessness and binge behavior.
Blood or plasma samples of Ketamine concentrations are usually in a range of 0.5-5.0 mg/L in patients receiving the drug therapeutically (general anesthesia, etc.), 1-"2 mg/L in individuals arrested for impaired driving and 3-"20 mg/L in victims of acute fatal overdosage.